Device for moving a machine member or other part, by power means, an exact distance or to an exact position



DORAN ET AL DEVICE FOR MOVING A MACHINE MEMBER OR OTHER PART, BY POWER 5Sheets-Sheet 1 July 9, 1935. J. E.

MEANS, AN EXACT DISTANCE OR TO AN EXACT POSITION Filed May 7 1934ATTORNEY.

July 9, 1935. J E, DORAN -r A 2,007,180

DEVICE FOR MOVING A MACHINE MEMBER OR OTHER PART, BY POWER MEANS, ANEXACT DISTANCE OR TO AN EXACT POSITION Filed May 7, 1934 5 Sheets-Sheet2 5 a AK/Q r/ AHV 4% ATTORNEY.-

y 1935- J. E. DORAN EB AL 2,607,189

DEVICE FOR MOVING A MACHINE MEMBER OR OTHER PART, BY POWER MEANS, ANEXACT DISTANCE OR TO AN EXACT POSITION ATTORNEY.

July 9, 1935. J E. DORAN ET L 2,007,180

DEVICE FOR MOVING A MACHINE MEMBER OR OTHER PART, BY POWER MEANS, ANEXACT DISTANCE OR TO AN EXACT POSITION Filed May '7, 1954 5 Sheets-SheetJuly 9, i J E DORAN ET AL 2,007,180

DEVICE FOR MOVING A MACHINE MEMBER OR OTHER PART, BY POWER MEANS, ANEXACT DISTANCE OR TO AN EXACT POSITION Filed May 7, 1934 5 Sheets-Sheet5 Patented July 9, 1935 UNITED STATES PATENT OFFICE TION John E. Doran,John M. Walter, and Forrest E. Cardullo, Cincinnati, Ohio, assignors toThe G. A. Gray Company, Cincinnati, Ohio Application May 7, 1934, SerialNo. 724,304

18 Claims.

The purpose of our invention is to provide power means for moving aheavy machine member, such as the table of a planer-type millingmachine, or of a jig borer, or the head of a planertype milling machineor jig borer, to any particular point in its travel, or to move it anydesired distance (within a fraction of a thousandth of an inch) from onepoint to another point in its line of travel without the necessity ofproviding a mechanical stop against which the moveable member is forced.

Hitherto, it has been necessary in order to exactly position a machinemember either to push it forcibly against a fixed or adjustablemechanical stop, which is inaccurate at best and harmful to themechanism, or else to move it into place by means of a hand crank andscrew, or some other manually operated mechanism, which is a slow, andin the case of a heavy part of a large machine, a laborious operation.We avoid this by using power means for moving the member and directacting control means for finally stop ping the power means at preciselythe right point. In order to expedite a movement of any considerabledistance, we employ two power means, one of which is adapted to move theelement rapidly, and the other of which is adapted to move the elementslowly and precisely. In order that the moveable member shall stop atthe desired point, we provide means, consisting of a part of themoveable member itself, or of a part attached thereto, which touches andmoves a moveable control element which actuates control apparatuslocated on the part on which the member moves or slides, whichslows-down and stops the motor or motors which move the moveable member,after the moveable control element has been moved by a certain definiteamount, or in a certain definite time after the control means or somepart of it has been actuated.

Alternatively, the control means may be attached to the nioveable memberand the projection actuating the control means may be a part of orattached to the fixed member of the machine.

In order to measure a precise distance, we make use of an apparatusconsisting of an index slide adapted to be moved in a guide or carrier,which may be attached to, or form part of either the moveable or thefixed member. In a part of this guide, we machine holes of identicaldiameter having exact distances apart, preferably 1" from center tocenter. A plunger in the index slide of such a size as to just enter thehole may be inserted in any one of the holes, whereby the index slidemay be moved any desired integral number of inches with great exactness.To the index slide may be attached a micrometer head, the anvil of whichis adapted to actuate the control means by contact. Alternatively, themicrometer head may be attached to the moveable control element, whichwill then be moved by contact between the anvil of the micrometer headand a projection on the index slide, or the micrometer, the moveablecontrol element, and the control means may slide on the guide orcarrier, the control means being actuated by contact between a.projection on the fixed or moveable member and the micrometer anvil. Bythis means, the actuation of the control means may be readily caused tooccur at any position of the moveable element, and having occurred itmay be caused to occur again at any position at any desired distancefrom the first, thus movin the moveable elem nt by any desired exactdistance.

Furthermore, in order to eliminate any possibility of error, we embodyin the control apparatus what is known as a dial indicator, having arevolving hand which indicates thousandths of an inch movement. In usethe dial indicator is adjusted so that the hand points to zero when thecontrol apparatus has stopped the moveable member, and any deviationfrom the Zero after any subsequent movement and stoppage of the moveablemember indicates the amount of inaccurac which may be corrected bybacking off the moveable member and again moving it into position untilthe control means stops it with the hand pointing to zero, or by makingcompensation for the amount of error indicated by the dial indicator.When the moveable member is correctly stopped by the control means it issaid to be in index position.

In the drawings, Fig. 1 is an isometric projection of a planer-typemilling machine having one head on the rail. Fig. 2 is a horizontalsection in the plane of the motor shafts through the gear box on Fig. 1,showing the gearing which connects the positioning motor 3, which mayalso be the feed motor, with the rapid traverse motor 5, and also themagnetic clutch which connects or disconnects the gearing driven bymotor with the: gearing driven by motor 3. Fig. 3 is a front view of theindex carrier which is attached to the side of the table of the millingplaner. Fig. 4 is a longitudinal section through the index carrier online 44 of Fig. 3. Fig. 5 is a cross section of the index carrier online 5-5 of Fig. 3. Fig. 6 is a diagrammatic drawing of a quick actingswitch which may be employed to stop the table at a desired position inits travel. Fig. 7 is a simplified circuit diagram for operating motor 3with the quick acting switch shown in Fig. 6. Fig. 8 is a simplifiedcircuit diagram for operating motor 3 when two close motion switches areemployed in order to stop motor 3 with the table in a desired position.Fig. 9 shows the arrangement of the parts: usually employed in thecontrol box 5. Fig. 10 is an end view of the control box 5 and of thebracket on which it slides. The greater part of Fig. 9 is a section onthe line 99 of Fig. 10, while the upper right hand portion is brokenaway to show a. section on line 9a9a of Fig. 10 in order to explain theadjusting mechanism by which box 6 is. moved.

Fig. 11 is a diagrammatic sectional drawing of a single throw closemotion switch of a type which we employ. Fig. 12 is a diagrammaticsectional drawing of a double throw close motion switch of a type whichwe employ. Fig. 13 is a simplified circuit diagram for operating motors3 and 5,'when rapid traverse is employed and six close motion switchesare used in order to rapid traverse and stop both table 2 and millinghead l02,.in desired positions. Fig. 1% is a portion of a verticalsection through box t in the plane of the axis of the shaft of motor 5.Fig. 15 is a diagrammatic representation of switches actuated by acontrol handle 59 which also actuates clutch means alternatively toconnect the motors 3 and 5 with the table moving mechanism or the headmoving mechanism. Fig. 16 is a simplified circuit diagram showing analternative method for stopping the positioning motor 3.

Inall of the simplified diagrams the contacts are represented in theposition which they have when the entire circuit is deenergized and. the

switches are represented in the position which they have when themoveable control element is not touched. The contacts in the descriptionare stated to be normally open if they are open when the coil of thesolenoid which actuates them is deenergized. Such contacts are closed bythe movement of the solenoid when the coil is energized.

Contacts which are stated to be normally closed. are closed when thecoil of the solenoid which actuates them is deenergized and suchcontacts are opened by the movement of the solenoid when the coil isenergized. After the coil of any so1enoid is deenergized, a spring orweight returns the contacts to their normal condition, in the mannerusual in the art, unless a member specifically described, prevents suchaction.

v Referring to the drawings, l is the bed of a planer-type millingmachine. 2 is the table which slides along the bed of the millingmachine. 3 is a motor which, by means of gearing partly contained ingear box 1 and partly contained in bed I, serves to move the tableslowly and precisely into position. The kind of gearing employed is notof importance and forms no part of this invention. It is only necessarythat the gear reduction be sufiicient so that when motor 3 is revolvingat its lowest normal speed, the table 2 travels at the rate of somewherebetween and 4 per minute. 5 is a motor which serves to rapid traversethe table at any suitable speed, say 15 to 20 feet per minute. Motor 5is connected to the gear train where the speed of rotation of thegearing is only a fraction of that of motor 3. When energized motor 3will cause the armature of motor 5 to revolve slowly. The

gearing driven by motor 3 is connected to the t, is forced to the leftby spring H.

gearing driven by motor 5 by means of a magnetic clutch 38, as shown inFig. 2, or by means of any other suitable type of clutch.

Throughout this disclosure, a magnetic clutch is assumed, although otherclutches disengaged by the rotation of motor 5 may be and have beenemployed. The purpose of the magnetic clutch is to disconnect thegearing intermediate between motor 3 and motor 5 when motor 5 isenergized, so that motor 3 will not be driven by motor 5, since if thegearing driven by motor 3 were not then disconnected, motor 3 would bedriven by motor 5 at dangerously high speed, and the gearing between thetwo motors severely strained.

Fixed to the side of the bed is control box 6 which will be described indetail later, and from which projects micrometer head l-a, the anvil ofwhich can be adjusted through a distance of 1". When the micrometer headis caused to move by the index slide advancing against it, the controlmeans functions in such a way as to first stop motor 5, then to engagethe magnetic clutch, then to slow down and finally to stop motor 3 sothat the table, after rapid traversing, moves slowly and finally comesto rest in index position.

To the side of the table is .fixed a carrier 8 shown in detail in Fig.3. In this carrier is planed a dovetail slot 8-11 and at the bottom ofthis, a rectangular slot 8-4) in which are screwed a number of indexbars 9. We prefer to make these index bars rectangular in section andexactly 10 long. In each bar are machined ten cylindrical holes Sa, allof exactly the same diameter and the center of each exactly one inchfrom the center of the adjacent holes. The centers of all of the holeslie on a line exactly parallel with the edges of the bars. Also, in eachbar are drilled and countersunk two or more holes 9b in which are screwsH) which serve to fasten the index bars to the carrier.

Sliding in the dovetail of the carrier, is slide H in which is machineda cylindrical hole I la in which are pressed bushes l2 and I3. Bush 12is bored to the same diameter as the holes in the index bars, whilebushlS is bored to the same diameter as the stem of the index plunger14. The large end l4-a is a snug fit in bush i2 and also in any of theholes in the index bars, while the small end Mb is a snug fit in bushi3. Between bush [3 and the end Ma of plunger i4 is spring it whichtends to press the plunger into a hole in the index bar. At the end ofthe plunger is fastened a knob !6 by which the plunger can be pulled outor pushed into any one of the holes in the index bars. On slide 1 l isprojection l |-b which is adapted to impinge on the anvil of themicrometer head 'la whenever the table is so moved as to cause the twoto make contact.

In order to explain the theory of the electrical control mechanism bywhich the operation of bringing the table to rest is performed at agiven point in its path, it will be assumed that the quick acting switchshown diagrammatically in Fig. 6 is contained in control box 6. In thecontrol box is a control slide l on the end of which is a micrometerhead not shown in Fig. 6. In the control slide 1 is a hole in which isbush 'lb, the edges of the bush being sharp and the bush being hardened.Slide 1, which moves smoothly in a hole machined in the control box Whenthe projection Hb on slide H encounters the anvil of the micrometer headastable 2 moves, slide '3 is forced against spring I! until the hole inbush l-b comes opposite the hardened end ncctor |8-b connects contactpoints 2|. As

soon, however, as spring |9 forces the stem |8 downward, the circuitbetween contact points 20 and the circuit between contact points 2| isinterrupted, and the stem continues downward until connector |8bestablishes a circuit between contact points 22.

Referring now to Fig. '7 thecircuit so operated'is there shown, in whichcontacts 20, 2| and 22' are shown as normally open or normally closedaccordingly as to whether they are connected by their respectiveconnectors or not when the quick acting switch is in its upper positionas shown in Fig. 6. 23-11. and 23-19 are the two supply lines. 24 is apush button. When push button 24 is pressed, supply line 23-11. isconnected to supply line 23-b through coil 25 which, upon beingenergized, first opens normally closed contacts 25c, and then closesnormally open contacts 25a and 25-1).

This establishes a circuit from line 23-11 through normally opencontacts 25a motor 3, the now connected contacts 20 of the quick actingswitch, and the normally open contacts 25--b to line 23-4). The field ofthe motor 3-4, has already been energized when voltage was applied tolines 23a and 23b by closing a knife switch, or in any other suitablemanner. Motor 3 thereupon begins to revolve in such a direction as tocause the table to move toward index position and continues to revolvein this direction until control slide 1 is moved by index slideprojection ||b far enough so time causes dynamic braking by connectingcontacts 22, which allows current from the armature of motor 3 to flowthrough contacts 22, normally closed contacts 29-c and dynamic brakingresistance 26, bringing the motor quickly to rest, and stopping thetable in index position.

When the thumb is released from push button 24, coil 25 will bedeenergized, contacts 25-a and 25-b will be opened and contacts 25-0will be closed.

When it is desired to move the table in the opposite direction, that is,away from index position, button 21 is pressed. Since contacts 2| arenow disconnected, coil 23 will be energized and coil 29 will not beenergized. Energizing coil 28 causes the stem l8 of the quick actingswitch to be lifted against the pressure of spring It], thusdisconnecting contacts 22, connecting contacts 20, and also connectingcontacts 2|. The

. connecting of contacts 2| causes coil 29 to be energized whichthereupon opens normally closed contact 29c and closes normally opencontacts 29-a and 29-b. This causes motor 3 to revolve in the directionwhich causes the table to move away from index position.

Immediately, spring I! pushes control slide 1 into such a position thatstem l8 can no longer move downward, and when the table has moved asufiicient distance, the finger is removed from button 21 whichdeenergizes coils 28 and 29, thereby allowing spring Hi again to pressstem l8 downward against control slide 1, and opening contacts 29--a and29--b and closing contact 29-c, whereby motor 3 is brought to rest bydynamic braking.

A more delicate adjustment of the table may be obtained by employing thecircuit shown in Fig. 8 in which 23-a and 23-42 are the supply lines, 3the motor armature, 3-F the motor field, 24 the push button to cause thecontrol to move the table to the index position, 21 the push buttonwhich causes the control to move the table in the reverse direction, oraway from the index position, and coils 25 and 29 have similar functionsto those which they had in the previous circuit.

On pressing button 24, coil 25 is energized which closes normally opencontacts 25-11 and 25b. permitting current to flow from line 23-a,through 25-a, through normally closed contacts ill-a, through motorarmature 3, and through contacts 25-4) to line 23-b, and causing themotor armature to revolve in such a direction as to advance the table toindex position.

In order to understand the action of this circuit, it will be necessaryto refer to Fig. 9, in which 6 is the control box in which slides amovable control element which control slide 1, on the end of which ismicrometer head '|--a. Inside of control box 6 are three close motionswitches 30, 3| and 32. Switch 39 takes no part in the action when arapid traverse motor is not employed, and therefore does not appear inthe circuit shown in Fig. 8. These switches may be a commercial productand are described in Patent No. 1,780,578. Switches 30 and 3| are shownin section in Fig. 11. They consist of a case of insulating material 33,in which is a leaf spring which is attached at one end to a conductingblock 34-a and to the other end of which is attached contact 34-b. Nearthe center of its length, the spring 34 presses against abutment 33-a.Against the leaf spring, when it is in its normal position in ourdevice, there presses a plunger 35, of insulating material, which holdsthe contact 34-49 away from the contact 36. However, if plunger 35 isallowed to move upward, at a certain point in its movement the leafspring 34 will snap into the position shown, where 34-4) makes contactwith 36, so that current may flow between conducting block 34-a andcontact 36 through leaf spring 34, which is of conducting material.

The form and temper of the leaf spring is such that only a very slightdownward movement of plunger 35 is required to deform the spring in sucha manner as to move contact 34-b a considerable distance away fromcontact 31.

Switch 32, shown in Fig. 12 is similar to switches 38 and 3| except itis supplied with a second contact 31. When plunger 35 of spring 33 isdepressed slightly, as is the case in the normal position, the leafspring 34 is deformed in such a way that it holds contact 34--b againstcontact 31, and current may flow between 34-a and 31. When plunger 35 isallowed to move a few thousandths of an inch, at a certain point in itsmovement the leaf spring snaps 34-4) into contact with 36 so that thecircuit between 34-11 and 3'1 is suddenly broken, and one is completedbetween 34 a and 36.

Within control box 6' is a hole in whichslides plunger 38, held againstcontrol slide 1 by spring 39, the end of plunger 33 engaging the plunger35 of switch 3| and holding contact 3 l-b away from contact 36 so thatswitch 31 is normally open as shown in Fig. 8. As the index slideprojection l I--b moves control slide 1 to the right, shoulder l-cpasses over the end of plunger 38, permitting spring 39 to raise it,which permits switch 3| to close with a snap.

This energizes coil 15 which opens normally closed contacts 4ila andcloses normally open contacts 4[I-b, thus compelling the motor armatureto receive its current through a high resistance 4 I, and thence throughcontact 3'! of switch 32. This greatly reduces the electromotive forceimposed on the motor armature, and causes the motor to slow down to alow speed. The motor continues to mm in the same direction, slide Imoving to the right until bracket l-d, attached to slide 1, comes incontact with the end of stem 42-0, of dial indicator 42. Immediately,the hand of the indicator begins to revolve, and as stem 42a moves tothe right, the right hand end of the stem presses against one arm 43a ofbell crank lever 43. This arm is moved slightly against spring 44, whichhas been holding the bell crank in such a position that the other arm43b has been pressed against plunger 35 of switch 32. As soon as alt-bhas moved a few thousandths of an inch, leaf spring 3d of switch 32snaps contact 34b away from contact 3'! and against contact 36.

The armature of motor 3 no longer having an impressed electromotiveforce, and being short circuited through switch 32 and normally closedcontacts 29c, it is immediately brought to rest by dynamic braking withthe table in index position. ,Since the motor armature has just beenoperating under greatly reduced voltage and at low speed, the energy tobe dissipated by dynamic braking is small, and a dynamic brakingresistance is not necessary nor advisable.

The purpose of contacts 4!lb is to prevent potential difference fromoccurring between contacts 35 and 3"! and so to reduce the liability ofswitch 32 to injury.

In order that contacts 3 lb and 37 shall not be pitted by arcing whenthe circuit is broken, condenser 45 may be inserted in the circuitbetween contact 3l and conducting block 34a. This condenser is notessential to the action of the control, and has no effect except toprolong the life of switch 32.

In order that the operator may know when the indexing operation iscomplete, a small electric light bulb 65 is connected in parallel withcondenser 45. When switch 32 is in such a position as to shunt condenser45 and bulb 65, any current flowing through resistance 4! will flowthrough the switch and not through the bulb. However, when switch 32 isallowed to snap, contact 34---] will touch contact 35 instead of contact31, and current will flow through resistance 4!, through the bulb,through switch 32, and contacts 29--c and 40-h, permitting the bulb 55which had previously been short circuited, to light. The lighting of thebulb acts as an electrical signal, informing the operator that themovement of switch 32 is completed, and that he may release his fingerfrom the button.

When the finger is removed from button 24 coil 25 will be deenergized,opening contacts 25a and 25b. If button 24 is again inadvertentlypressed, nothing will happen since coil move the table away from indexposition. Spring 46 on control slide 1 immediately presses bracket ldaway from the stem l2a of indicator 52.- Spring 44 immediately movesbell crank 43, which presses on plunger 35 ofswitch' 32 causing its leafspring 34 to snap contact 3 lb from contact 36 to contact 31. Since thecircuit which includes 3 t-a and 36 has been interrupted at 29-c, nocurrent is flowing at the time that 3 ib separates from 36 and no arcingoccurs. The motor continues to revolve until spring 35 presses theshoulder 1-0 against plunger 38, forcing it down into contact withplunger 35 of switch 3!, open.- ing this switch which is in a circuitincluding contacts 29-d which are now open, so that when switch 31 opensno current is flowing. l

When the table has moved to the desired point the finger is removed frombutton 21, deenergizing coil 23, which causes contacts 2ila and 23-b toopen and 29-0 and 29d to close, thus deenergizing the armature of motor3 and causing it to coast to rest.

Referring to Fig. 16, there is there shown an alalternative arrangementof a part of circuit shown in Fig. 8, which stops armature 3 in adifierent manner. Assume that the armature of motor 3 is energizedthrough normally closed contact Mia in Figure 16. As soon as coil 43 inFig. 8 iscnergized Mia will be opened and dill) will be closed. Armature3 will thereupon receive its current through resistance 4 l and signalbulb 55 will light.

As soon, however, as switch 32a is caused to close by the movement ofthe moveable control element (single throw switch 32a taking the placeof double throw switch 32) armature 3 will be short circuited throughswitch 32a, whereupon dynamic braking will occur and the armature willcome to, rest. As soon as switch 32a closes bulb 65 will beextinguished. In this case switch 32a does not disconnect the armature 3from either supply line but merely applies dynamic braking, and becauseof its low resistance, diverts the currentv from resistance 4!, whichwould otherwise pass through the armature.

Referring to Fig. 14, 5-a is the extended shaft of motor 5 on which isslidably keyed a gear 5!. This gear meshes with gear 52, shown in Fig.2, which is coupled to the gearing driven by motor 3 by means ofmagnetic clutch 48. Gear 5| has an extended hub 5 l-u, in which is agroove 5 i-b so that the gear may be shifted by fork 53. On each end ofgear 5! are cut clutch teeth 5 lc and 5id. The clutch teeth 55-0 engagewith corresponding clutch teeth out on bevel gear 5 3 which is bushedand turns freely on shaft 5-a and is retained in place by a wall of boxl. Gear 5 meshes with gear 55 which is keyed to shaft 555 which servesto drive the feed mechanism in box H34 at the end of rail Hill on whichmoves head Hi2. When fork 53 shifts gear 5! so that it is declutchedfrom bevel gear 54, it is clutched to clutch 57 which is keyed fast toshaft 55 which drives gearing not shown, containedwithin bed I, whichmoves table 2. It will thus be seen that when gear 5| is shifted to theleft, motors 3 and 5 serve to drive the table only, and when it isshifted to the right motors 3 and 5 are disconnected from shaft 56, andcoupled to bevel gear 55 which serves to drive the head along the railin the manner usual in the art.

Fork 53 is pinned fast to shaft 58 to which is pinned lever 59 at theend of gear box 4 so that by moving lever 59, table 2 or head I02 may becaused to move by means of motors 3 and 5, in the manner desired.

Link 60 fits a pin in lever 59, and also a pin in stem 6| which actuatesthe switches shown diagrammatically in Fig. 15, and also distributed inthe proper places in their circuits in Fig. 13. On stem 6| are threeconductors 62, 63 and 64, which when gear 5| is in position to operatethe table, touch the contacts shown, so as to close gaps in circuits inwhich are switches 30, 3| and 32. At the same time conductors I 62, I63and IE4 are separated from their coacting contacts, leaving gaps in thecircuits in which are switches I33, iill and I32. When lever 59 is movedso as to shift gear 5| from clutch engagement with clutch 51 on shaft56, which moves the table, and into clutch engagement with gear 54 whichmoves the head, stem 6| is so moved that conductors 62, 63 and 64 areseparated from their coacting contacts, interrupting the circuits inwhich are switches 30, 3| and 32, and conductors I62, I63 and I64 touchtheir coacting contacts, and close the gaps previously existing in thecircuits in which are switches I30, I3| and I32.

Switch 62 in series with switch 30, switch 63 in series with switch 3|,and switch 64 in series with switch 32, are closed by the movement ofstem 6| when gear IIlI is in such a position as to drive the table. Inthis position, switches I62, I63 and I64 are open. When, however, lever59 is so moved as to cause gear 5| to drive gear 54 and shaft I 56, sothat head I02 may be moved instead of table 2, the movement of stem 6|opens switches 62, 63, and 64, and closes switches I62, I63 and I64 sothat switches I30, I3I and I32 will control the stoppage of motors 3 and5. Since switches I30, I3I and I32 are contained in control box I66, themovement of the head is stopped when the head itself comes in contactwith the control slide in control box I06, and pushes it sufliciently toactuate the three switches.

It will thus be seen that the electrical equipment, except for the closemotion switches 30, 3| and 32 and I30, I3I and I32, is common to boththe head and the table.

Fig. 13 is a simplified wiring diagram of a circuit adapted to utilizeboth a rapid traverse inotor 5 and a positioning motor 3 to position twomoveable members, such for instance, as the table 2 and the millng headI02.

We will assume that the table will be positioned first, in which casethe clutch gear 5! will be in such a position that it will engage thetable driving mechanism, and because of the position of the lever 59,contacts 62, 63 and 84 will be closed and contacts I62, I63 and I64 willbe opened. 23a and 23b are supply lines as before. 3 is the positioningmotor with its field 3F. 5 is the rapid traverse motor with its field5-l and 24 is the push button which is pressed in order to move thetable toward index position. Pressing button 24 energizes coil 25 andsince contacts 46-a are normally closed, it also energizes coil 49.Energizing coil 25 closes contacts 25a and 25-4), and energizing coil 49opens contacts 49a and 49c and closes contacts 49-h. Since 49-c is nowopen, the coil 48--a of magnetic clutch 48 is deenergized, and gear 52may revolve without turning the gearing in box 4 driven by motor 3. Thearmature of motor 5 being energized, the table will be moved towardindex position. Also coil 50 will be energized, opening contacts 56a.When projection IIb on index slide touches micrometer head "I-a, controlslide '1' moves and bracket I-d moves away from the plunger of switch30, which closes, energizing coil 46.

This opens contacts 46a, deenergizing coil 49, which allows contacts49-h to open, and contacts 49-a and 49c to close, deenergizing thearmature of motor 5 and stopping it by dynamic braking throughresistance 41. So long as the armature generates counter electromotiveforce, coil 56 will be energized and contacts 50a will remain open. Whenthe armature of motor 5 comes to rest, contacts 50-44 will close, coll48c will be energized, and magnetic clutch 48 will engage.

During the time since 24 was pressed, the armature of motor 3 has beenenergized and running. As soon as clutch 48 engages, motor 3 begins tomove the table at a low rate of speed, and continues to do so until theshoulder 'I-c of the control slide I moves past plunger 38, releasingthe plunger of switch 3|, allowing it to close. This energizes coil 40which opens normally closed contacts 4Q-c and closes normally opencontacts 46-1). The armature of motor 3 now receives its current throughresistance 4|, switch 32, switch 54, and normally closed contacts 29-c,and runs at a much slower rate of speed.

Finally, bracket 'I-d makes contact with stem ii-a of dial indicator 42,actuating bell crank 43, allowing switch 32 to snap so that it makescontact with contact 36 instead of contact 3?, thus short-circuiting thearmature of motor 3 and bringing it to rest by dynamic braking. Whilestem 42a. of indicator 42 is moving, the hand of the indicator alsorevolves, indicating the position of control slide "I, the hand comingto rest when the control slide I and the table 2 also come to rest,which will be indicated by the lighting of bulb 65.

In use, the dial of the indicator is turned until the hand registerszero when the table has come to rest in index position. If the table isbacked away and then again brought into index position, the hand shouldagain point to zero, or else the error indicated should be Within theallowable limit of tolerance.

If, after the table comes to rest, button 24 is again accidentallypressed, since coils 40 and 46 are energized, contacts 46-a, 49-?) and40-a will be open, and neither of the motors can be energized.

When it is desired to return the table from index position, button 2'!is pressed, energizing coil 29. This immediately opens contacts 29-c,29-43, 25l-e and 23--] which deenergizes coils it? and permitting 46-ato close and 49 to be energized. Also, 29 a and 29-22 will close, aswill Mi -b, thus energizing the armature of motor 5.

Obviously with 29 open, coil 48--a of mag netic clutch i8 cannot beenergized. The armature of motor 5 will revolve in such a direction asto back the table away from indexed position, opening successivelyswitches 32, 3I and 30 which, however, are not at that time carryingcurrent. When the finger is removed from button 27, all contactorsreturn to the condition shown in Fig. 13 as soon as the dynamic brakingcycle of motor is completed, permitting contacts 5fl,a to close.

If it is desired to move the head toward index position, lever 59 israised, causing gear 5! to make clutch engagement with gear 54, openingswitches 62, 63 and (i l, and closing switches M2, 163 and [65. Thetable will no longer move, but shaft I56 acting through the gearing inbox W4 and through a feed screw not shown provided for moving the headI02, when button is pressed, will move the head toward the indexposition, As it approaches index position the control slide in controlbox H16, in which are also contained switches E30, 53! and 132, willbegin to move, the switches being actuated in the order named, andperforming the same functions respectively as switches 30, iii and 32,and the mechanism will act to bring the head to rest in index positionin an exactly similar manner as it did when the table was brought torest in index position.

Pressing button 2"! will cause the electrical mechanism to act to movethe head away from index position, in the same way as it acted whenmoving the table away from index position.

In case the head or the table does not come accurately to indexposition, as shown by the hand of the indicator, pressing button 2'! tomove it away and then pressing button 2 to move it again into indexingposition, will correct the error, unless it is due to some persistentimperfectionin the operation of the motors and controls.

It will be noted that the close motion switches are so arranged in thecircuits as not to break contact when transmitting current, except thatswitches 32 and I32 break contact when transmitting a very smallcurrent. The effect of this may be minimized by the use of condenser 15,connected in the manner shown. It is not essential that the circuits bearranged in this manner, since the switches are capable of breaking thecurrents required to actuate the relays, but by arranging them in thismanner, any chance of damage from arcing may be avoided. It will also benoted that the mechanical parts move away from the switches when theswitches are caused to function, so that any overrrunning of themechanical parts cannot damage the switches. Finally, a signal bulb 65is inserted in the circuit in the manner shown, so that it will lightwhen not short circuited by switch 32 or switch I32, and so indicate thefinal completion of the indexing operation.

Referring to Figs. 9 and 10, it will be noted that the control box 8slides upon two cylindrical bars 6% and M. The upper bar Bl is threadedat one end and on it is thumb nut 63. At the other end of the bar isspring 69 which forces box 6 against the thumb nut. The purpose of thethumb nut is to adjust the mechanism so that the micrometer will readzero at the starting point of a job. l

The method of using the apparatus is as follows:

Assume that a piece of work is placed on the table, in which one or moreholes are to be bored. The longitudinal distance of the center of eachhole from a transverse vertical plane which passes through some point onthe work, such as the. end, or the center of the first hole, is assumedto be known. This plane may be called the transverse zero plane.

Thethumb nut 68 is screwed all the way back,

cator is then set so that the hand points to zero.

The longitudinal distance from the axis of. the spindle to thetransverse zero plane of the work, from which subsequent measurementsare to be made, is then measured. The index slide is then moved adistance equal to the number of integral inches from the spindle axis tothe zero plane and the micrometer is set to read the decimal part of aninch remaining. The table is again brought to index position, and thetransverse zero plane will then contain the spindle axis. The micrometerhead l-c is then set to read zero, and the thumb nut 68 is turned untilthe indicator hand again points to zero. The hole in the index slidecarrier, in which the index plunger then is, is the zero hole. If theindex slide be again moved a given distance, say five inches, and thetable again indexed, the spindle axis will be five inches from thetransverse zero.

proper decimal of an inch, and then indexing the table, the table willcome to rest with the spindle axis over the work, and at the properlongitudinal distance from the transverse zero plane.

Similarly there will be a longitudinal zero plane, and by indexing thehead, measuring the distance from the spindle axis to the longitudinalzero plane, backing the head away, setting the index box 36 over theproper number of inches, and setting the micrometer to indicate theremaining decimal, and again indexing the head, the spindle axis willlie in the longitudinal zero plane. It will be understood that the indexbox H on the head is provided with means of adjustment similar inprinciple to the adjustment shown for box 6, so that the indicator inbox I06 may be made to read zero when the plunger of this box is in thezero hole, and the micrometer is set to read zero.

By successively indexing the table and the head to the two coordinatesmeasured from the two zero planes, as shown on or figured from thedrawings provided for performing the work, the table and the head may bebrought into such relative position that the spindle axis will passthrough the required point on the upper surface of the work.

After completing the boring of the first hole, the table and head willbe indexed so that the spindle axis coincides with the axis of thesecondhole, and so on to the completion of the work.

It will be apparent that the head, the table, or both, may be indexed ina similar manner for performing other operations than boring, or for anyother purposes for which such a device may be useful.

The essential features of the invention are the use of a direct actingcontrol element such as the quick acting switch shown in Fig. 6, or theclose motion switch 32, to complete the stoppage of the positioningmotor when it is running at a sufiiciently slow speed so that themovable member will be positioned with the requisite accuracy, the useof the dial indicator, or some analagous device, to check the accuracyof the index position by indicating the position of the movable controlelement when stopped after indexing, and the use of an incrementalmeasuring device in connection with a micrometer head to make themeasurements of the different index positions convenient andexpeditious. Furthermore the measuring device is used in such a mannerthat it is one of the chain of functional elements interposed betweenthe movable member and the fixed member, which, working together, stopthe movable member in the desired position relative to the fixed member.

In the device disclosed the direct acting control element or switch doesnot function through relays or other devices, but when its action hasbeen initiated by the movable control element at a certain definitepoint in the movement of the latter, the direct acting controldeenergizes and dynamic brakes the positioning motor. However, any typeof control device which will func tion with sufiicient rapidity anduniformity after the movable control element reaches a certain definiteposition, will serve as well. In its entirety the invention providesmeans for rapid traversing the movable member with one power means, iorautomatically changing from rapid traverse to slow motion obtained froma second power means, for still further slowing the rate of slow motionand for stopping the movable member in its desired position by stoppingthe second power means, measuring means, indicating means, and sir nalmeans, together with control means for moving the movable member backfrom its index position.

It is obvious that the several parts of the apparatus described may bearranged in many dif ferent ways without in any way changing thefunctions or purpose of the parts. Also any one familiar with the use ofelectrical control devices may re-arrange the circuits in many ways andstill accomplish the same results.

Furthermore, hydraulic or pneumatic equipment may be substituted for theelectric equipment, by using for control means suitable interconnectedvalves instead of the coils and contacts, in order to rapid traverse andthen slowly position the moveable member, and then by using a directacting inultiported valve, to quickly shut oh the inflow and outflow ofthe fluid to and from the cylinder or fluid motor, at a certain.definite position in the movement of a moveable control pended claims.

What is claimed is,

1. In combination, a fixed member, a moveable member, power meansadapted to cause the moveable member to move with reference to the fixedmember at a suitable speed, control means for causing the power means tomove the moveable member toward a desired position. a direct actingcontrol element for stopping the power means, and a moveable controlelement actuated by the movement of the moveable member as it approachesthe desired position, adapted to initiate the action of the directacting control element when the said moveable control element reaches adefinite position in its movement.

2. in combination, a fixed member, a movoable member, power meansadapted to cause the moveable member to move with reference to the fixedmember at a suitable speed, control means for causing the power means tomove the moveablomember toward a desired posit-ion,

a direct acting control element to stop the power means, a moveablecontrol element actuated by the movement of the moveab-le member as itapproaches the desired position, adapted to initiate the .ction of thechrect acting control element when the said moveable control elementreaches a definite position in its movement, and means for indicatingthe position of the moveable control element when stopped.

3. In combination, a fixed member, a moveable member, power meansadapted to cause the moveable member to move with reference to the fixedmember at a suitable speed, control means for causing the power means tomove the moveable member toward a desired position, a direct actingcontrol element to stop the power means, a moveable control elementactuated by the movement of the moveable member as it approaches thedesired position, adapted to initiate the action of the direct actingcontrol element when the nioveable control element reaches a definiteposition in its movement, and means for indicating when the directacting control element has functioned.

i. In combination, a fixed member, a movable member, power means adaptedto cause the moveable member to move with reference to the fixed memberat a suitable speed, control means for causing power means to move themoveable member toward a desired position, a direct acting controlelement to stop the power means, a moveable control element actuated bythe movement of the moveable member as it approaches the desiredposition, adapted to initiate the action of the direct acting controlelement when the said moveable control element reaches a definite poition in its movement, and measuring means adapted to affect therelative position of the moveable member and the fixed member when themotion of the moveable member initiates the action of the direct actingcontrol ele ment.

5. In combination, a fixed member, a moveable member, power meansadapted to cause the rnoveabi member to move, a first control means forcausing the power means to move the moveable member toward. a desiredposition, a second con .01 means for slowing down. the motion of thepower means to a suitable rate, a third control means for stopping thepower means, and a moveable control element actuated by the movement ofthe moveable member as it approaches the desired position, adapted toactuate the second control means when it reaches a first position. inits movement, and to actuate the third control means when reaches asecond and definite position in its movement.

6. In combination, a fixed member, a moveable member, power meansadapted to cause the moves-ole member to move, a first control means forcausing the power means to move the moveable member toward a desiredposition, a second control means for slowing down the motion of thepower means to a suitable rate, a third control means for stopping thepower means, a moveable control element actuated by the movement or" themoveable member as it approaches the desired. position, adapted toactuate the second control means when it reaches a first position in itsmovement. and to actuate the third control means when it reaches asecond and definite position in its movement, and means for indicatingthe position of the inoveable control element when stopped.

'7. In combination, a fixed member, a moveable member, power meansadapted to cause the moveable member to move, a first control means forcausing the power means to move the moveable member toward a desiredposition, a second control means for slowing down the motion of thepower means to a suitable rate, a third control means for stopping thepower means, a moveable control element actuated by the movement of themoveable member as it approaches the desired position, adapted toactuate the second control means when it reaches a first position in itsmovement, and to actuate the third control means when it reaches asecond and definite position in its movement, and means for indicat ingwhen the third control means has functioned.

8. In combination, a fixed member, a moveable member, power meansadapted to cause the moveable member to move, a first control means forcausing the power means to move the moveable member toward a desiredposition, a second control means for slowing down the motion of thepower means to a suitable rate, a third control means for stopping thepower means, a moveable control element actuated by the movement of themoveable member as it approaches the desired position, adapted toactuate the second control means when it reaches a first position in itsmovement, and to actuate the third control means when it reaches asecond and definite position in its movement, and measuring meansadapted to afiect the relative position of the moveable mem her and thefixed member when the motion of the moveable control element actuatesthe third control means.

9. In a measuring device, an index slide carrier having guiding waveformed integral therewith and equal holes spaced equi-distanttherealong, an index slide adapted to be guided by said guid ing ways, aplunger in the index slide adapted to engage any of the said holes forexactly locating the index slide relative to the carrier, and amicrometer head used in conjunction therewith. 10. In a measuring deviceassociated with a fixed member and moveable member, an index slidecarrier having guiding ways formed integral therewith and equal holesspaced equi-distant therealong, an index slide adapted to be guided bythe said'guiding ways, a plunger in the slide adapted to engage any ofthe said holes for exactly locating the index slide relative to thecarrier, a micrometer head used in connection therewith, a moveablecontrol element, and indicating means adapted to show the position ofthe moveable control element during part of its motion.

11. In combination, a fixed member, a moveable member, a motor adaptedto move the moveable member upon the fixed member, control means forcausing the motor to move the moveable member toward a desired position,a direct acting switch for stopping the motor, and a moveable controlelement actuated by the movement of the moving member and adapted toinitiate the action of the direct acting switch at a particular point inthe movement of the moveable control element.

12. In combination, a fixed member, a moveable member, a motor adaptedto move the moveable member upon the fixed member, manually operablemeans adapted to cause the motor to move the moveable member toward adesired position, a moveable control element actuated by the movement ofthe moveable member, a first control means actuated by the moveablecontrol element and adapted to cause the motor to move at a slower rate,and second control means actuated by the moveable control element whenmoved to a definite position, adapted to stop the motor. 1 v

13. In combination, a fixed member, a moveable member, a motor adaptedto move the moveable member upon the fixed member at a suitable speed,manually operable control means adapted to cause the motor to move themoveable member toward a desired position, a moveable control elementactuated by the movement of the moveable member, a direct acting controlelement actuated by the moveable control element when in a definiteposition and adapted to stop the motor, indicating means actuated by themoveable control element adapted to show the position of the moveablecontrol element when stoppechand measuring means adapted to afiect therelative position of the fixed and moveable members when the motion ofthe moveable control element initiates the action of the direct actingcontrol element.

i l. In combination, a fixed member, a moveable member, power meansadapted to move the moveable member upon the fixed member, a firstmanually operable control means adapted to cause the power means to movethe moveable member toward a desired position, a moveable controlelement actuated by the movement of the moveable member when itapproaches the desired position, a second control means actuated by themoveable control element and adapted to cause the power means to movethe moveable member toward the desired position at a'lower rate ofspeed, a third control means actuated by the moveable control elementwhen in a definite position and adapted to cause the power means tostop, an indicator actuated by the moveable control element and adaptedto show the position of the moveable control element when stopped, and afourth manually operable control means adapted to cause the power meansto move the moveable member away from the desired position.

15. In combination, a fixed member, a moveable member, a first motoradapted when energized or when revolved to move the moveable member uponthe fixed member, a train of mechanism adapted to revolve the firstmotor, a second motor adapted to drive the train of mechanism, automaticclutch means in the train of mechanism adapted to disconnect the trainwhen the first motor is energized and to reconnect the train when thefirst motor is deenergized, a first control means adapted to cause thefirst motor to move the moveable member toward a desired position, asecond control means adapted to stop the first motor by dynamic brakingwhen the moveable member is near the desired position, a third controlmeans adapted to cause the second motor to revolve at a lower rate ofspeed while continuing the motion of the moveable member toward thedesired position, a fourth control means for stopping the second motor,and a moveable control element for automatically actuating successivelythe second, third, and fourth control means.

16. In combination, a fixed member, a moveable member, a first motoradapted when energized or when revolved to move the moveable member uponthe fixed member, a train of mechanism adapted to revolve the firstmotor, a second motor adapted to drive the train of mechanism, automaticclutch means in the train of mechanism adapted to disconnect the trainwhen the first motor is energized and to reconnect the train when thefirst motor is deenergized, a first control means adapted to cause thefirst motor to move the moveable member toward a desired position, a.second control means adapted to stop the first motor by dynamic brakingwhen the moveable member is near the desired position, a third controlmeans adapted to cause the sec ond motor to revolve at a lower rate ofspeed while continuing the motion of the moveable member toward thedesired position, a fourth control means for stopping the second motor,a moveable control element for automatically actuating successively thesecond, third, and fourth control means, and means for indicating theposition of the moveable control element when stopped.

17. In combination, a fixed member, a moveable member, a first motoradapted when energized or when revolved to move the moveable member uponthe fixed member, a train of mechanism adapted to revolve the firstmotor, a second motor adapted to drive the train of mechanism, automaticclutch means in the train of mechanism adapted to disconnect the trainwhen the first motor is energized and to reconnect the train when thefirst motor is deenergized, a first control means adapted to cause thefirst motor to move the moveable member toward a desired position, asecond control means adapted to stop the first motor by dynamic brakingwhen the moveable member is near the desired position, a third controlmeans adapted to cause the second motor to revolve at a lower rate ofspeed while continuing the motion of the moveable member toward thedesired position, a fourth control means for stopping the second motor,a moveable control element for automatically actuating successively thesecond, third, and fourth control means, and means for indicating whenthe fourth control means has functioned.

18. In combination, a fixed member, a moveable member, a first motoradapted when energized or when revolved to move-the moveable member uponthe fixed member, a train of mechanism adapted to revolve the firstmotor, a second motor adapted to drive the train of mechanism, automaticclutch means in the train of mechanism adapted to disconnect the trainwhen the first motor is energized and to reconnect the train when thefirst motor is deenergized, a first control means adapted to cause thefirst motor to move the moveable member toward a desired position, asecond control means adapted to stop the first motor by dynamic brakingwhen the moveable member is near the desired position, a third controlmeans adapted to cause the second motor to revolve at a lower rate ofspeed while continuing the motion of the moveable member toward thedesired position, a fourth control means for stopping the second motor,a moveable control element for automatically actuating successively thesecond, third, and fourth control means, and measuring means adapted toaffect the relative position of the moveable member and the fixed memberwhen the motion of the move able control element actuates the fourthcontrol means.

JOHN E. DORAN. JOHN M. WALTER. FORREST E. CARDULLO.

